A New Synthesis of 24-Fluoro-1.ALPHA.,25-dihydroxyvitamin D2 and Its 24-Epimer, and Determination of the C-24 Configuration.
作者:Takaaki HAYASHI、Katsuji OJIMA、Katsuhiro KONNO、Akihiko MANAKA、Kentaro YAMAGUCHI、Sachiko YAMADA、Hiroaki TAKAYAMA
DOI:10.1248/cpb.40.2932
日期:——
A new synthesis of 24-fluoro-1α, 25-dihydroxyvitamin D2 (4a) and its 24-epimer (4b) is described. Starting with 1α, 3β-bis[(tert-butyldimethylsilyl)oxy]-24-norchol-5, 7-dien-23-al (5), a mixture of 4a and 4b was obtained in 3% overall yield in 6 steps. Reversed-phase HPLC cleanly separated the mixture into the two C-24 epimers. The X-ray crystallographic analysis of the 4-phenyl-1, 2, 4-triazoline-3, 5-dione (PTAD) adduct 11b, which was derived from the ester 6, unambiguously determined the configuration at C-24 of this compound. Based on the X-ray analysis, the configuration at C-24 of 4a and 4b was unequivocally determined.
本文描述了 24-氟-1α,25-二羟基维生素 D2(4a)及其 24-表聚物(4b)的一种新合成方法。从 1α,3β-双[(叔丁基二甲基硅烷基)氧基]-24-去甲胆-5,7-二烯-23-al (5)开始,经过 6 个步骤得到 4a 和 4b 的混合物,总产率为 3%。反相高效液相色谱法(HPLC)将混合物分离为两种 C-24 表聚物。对由酯 6 生成的 4-苯基-1, 2, 4-三唑啉-3, 5-二酮(PTAD)加合物 11b 进行的 X 射线晶体学分析明确确定了该化合物 C-24 的构型。根据 X 射线分析,明确确定了 4a 和 4b 的 C-24 构型。